Debra and Batista find proof that Neil Perry is the Ice Truck Killer when they find a body beneath Neil's trailer home. A manhunt ensues to find and capture Neil before he kills again. As more and more evidence rises to the surface, Dexter is left adrift. Neil Perry, the supposed Ice Truck Killer, doesn't live up to his expectations. Meanwhile, Dexter has to deal with his past when a teenager he caught and released murders again. As a result, Dexter sets out to correct this mistake in one of the only ways he knows how. Rita's family life is torn asunder as her paroled ex-husband, Paul, reasserts himself as the father of her children. Paul even confronts Dexter, letting him know that he doesn't like Dexter being around his wife and kids. Rita wishes that Paul would go away forever, something that is definitely possible when your boyfriend happens to be Dexter.

While looking into a series of suicides of high profile, powerful women, Dexter realizes a pattern: they all saw the same shrink. Dexter goes into stalk mode and becomes a patient of the shrink to ascertain whether or not he is the killer that he seems to be. Unexpectedly, the shrink helps Dexter unlock dark secrets from his past. Debra's latest relationship with Rudy also quickly heats up. Dexter's relationship with Rita, however, seems to be in danger as Paul works his way deeper into Rita's life and much to Rita's consternation, the kids love him and he's actually civil to her. Meanwhile, Dexter's certainty that Neil Perry is not the Ice Truck Killer helps LaGuerta to decide to not just accept Neil's confession, despite mounting evidence to the contrary.

Dexter receives a registered letter that informs him that his biological father has recently died. This comes as a shock, because Harry, Dexter's adoptive father, had told Dexter that his real father had died over 30 years ago. As Dexter takes off to reconnect to his shadowy past, Rita decides to come along to help him make it through the weekend. Then Debra and Rudy join them for the weekend at the dead bio-dad's house and things become even more awkward. Back in Miami, Doakes is involved in the questionable shooting of a middle-aged Haitian man. Internal Affairs investigates and Batista has to decide if he's going to tell the truth about the shooting, or back Doakes' untrue version of the actual incident.